Noisy rattle

[Graham]

My car beginning to make a rattle noise on idle. If you rev it slightly to 900 rpm the rattle goes away, but once on tick over its quite noticeable.
Listened under the bonnet, and its coming from the chain area!

So is it due a chain replacement, or is the chain tensioners not working. ?

Its had oil changes every 5k with vx oil 10w 40 semi from 25k onwards, now on 119k. So its not down to lack of oil changes, and its not been driven hard, thrashed either.

What's the likely problem. Tensioners or replacement chain or both?

[HenryD]

First thing I would do is remove the auxillary drive belt and run the engine just to check if the noise is still there,the auxilary belt tensioner could be the cause of the noise.

[m8internet]

the auxilary belt tensioner could be the cause of the noise

When this bearing fails it gives off a metal to metal noise, rather than a rattle, and although more obvious at idle it can still be heard at all engine speeds

[HenryD]

When this bearing fails it gives off a metal to metal noise, rather than a rattle, and although more obvious at idle it can still be heard at all engine speeds

I was thinking more of the tensioner itself rather than the bearing.

[m8internet]

I was thinking more of the tensioner itself rather than the bearing.

If the tensioner itself had become slightly loose it is possible, but it is more common for the bearing to wear out